// 日志器模块
// 1. 抽象基类
// 2. 派生子类
#ifndef __M__LOGGER__
#define __M__LOGGER__

#ifndef _GUN_SOURCE
#define _GUN_SOURCE
#endif

#include "utils.hpp"
#include "level.hpp"
#include "format.hpp"
#include "logSink.hpp"
#include "looper.hpp"
#include <atomic>
#include <mutex>
#include <unordered_map>
#include <cstdarg>

namespace wzh
{
    class Logger
    {
    public:
        using ptr = std::shared_ptr<Logger>;
        Logger(const std::string &logger_name, LogLevel::values level, Formatter::ptr &formatter,
               std::vector<LogSink::ptr> &sinks)
            : _logger_name(logger_name), _limit_level(level),
              _formatter(formatter), _sinks(sinks.begin(), sinks.end()) {}
        const std::string& name()
        {
            return _logger_name;
        } 

        void debug(const std::string &file, size_t line, const std::string &fmt, ...)
        {
            if (LogLevel::values::DEBUG < _limit_level)
                return;

            va_list ap;
            va_start(ap, fmt);
            char *res;
            int ret = vasprintf(&res, fmt.c_str(), ap);
            if (ret == -1)
            {
                std::cout << "vasprintf failed\n";
                return;
            }
            va_end(ap);
            serialize(LogLevel::values::DEBUG, file, line, res);
            free(res);
        }

        void info(const std::string &file, size_t line, const std::string &fmt, ...)
        {
            if (LogLevel::values::INFO < _limit_level)
                return;

            va_list ap;
            va_start(ap, fmt);
            char *res;
            int ret = vasprintf(&res, fmt.c_str(), ap);
            if (ret == -1)
            {
                std::cout << "vasprintf failed\n";
                return;
            }
            va_end(ap);
            serialize(LogLevel::values::INFO, file, line, res);
            free(res);
        }
        void warn(const std::string &file, size_t line, const std::string &fmt, ...)
        {
            if (LogLevel::values::WARN < _limit_level)
                return;

            va_list ap;
            va_start(ap, fmt);
            char *res;
            int ret = vasprintf(&res, fmt.c_str(), ap);
            if (ret == -1)
            {
                std::cout << "vasprintf failed\n";
                return;
            }
            va_end(ap);
            serialize(LogLevel::values::WARN, file, line, res);
            free(res);
        }
        void error(const std::string &file, size_t line, const std::string &fmt, ...)
        {
            if (LogLevel::values::ERROR < _limit_level)
                return;

            va_list ap;
            va_start(ap, fmt);
            char *res;
            int ret = vasprintf(&res, fmt.c_str(), ap);
            if (ret == -1)
            {
                std::cout << "vasprintf failed\n";
                return;
            }
            va_end(ap);
            serialize(LogLevel::values::ERROR, file, line, res);
            free(res);
        }
        void fatal(const std::string &file, size_t line, const std::string &fmt, ...)
        {
            if (LogLevel::values::FATAL < _limit_level)
                return;

            va_list ap;
            va_start(ap, fmt);
            char *res;
            int ret = vasprintf(&res, fmt.c_str(), ap);
            if (ret == -1)
            {
                std::cout << "vasprintf failed\n";
                return;
            }
            va_end(ap);
            serialize(LogLevel::values::FATAL, file, line, res);
            free(res);
        }

    protected:
        void serialize(LogLevel::values level, const std::string &file, size_t line, char *str)
        {
            LogMag msg(level, line, file, _logger_name, str);
            std::stringstream ss;
            _formatter->format(ss, msg);
            log(ss.str().c_str(), ss.str().size());
        }

        virtual void log(const char *data, size_t len) = 0;

    protected:
        std::mutex _mutex;
        std::string _logger_name;
        std::atomic<LogLevel::values> _limit_level;
        Formatter::ptr _formatter;
        std::vector<LogSink::ptr> _sinks;
    };

    class SyncLogger : public Logger
    {
    public:
        SyncLogger(const std::string &logger_name, LogLevel::values level, Formatter::ptr &formatter,
                   std::vector<LogSink::ptr> &sinks)
            : Logger(logger_name, level, formatter, sinks) {}

    protected:
        void log(const char *data, size_t len)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            if (_sinks.empty())
                return;
            for (auto &sink : _sinks)
            {
                sink->log(data, len);
            }
        }
    };

    class AsyncLogger : public Logger
    {
    public:
        AsyncLogger(const std::string &logger_name, LogLevel::values level, Formatter::ptr &formatter,
        std::vector<LogSink::ptr> &sinks, AsyncType looper_type)
        : Logger(logger_name, level, formatter, sinks), 
        _looper(std::make_shared<AsyncLooper>(std::bind(&AsyncLogger::realLog, this, std::placeholders::_1), looper_type)) {}

        void log(const char *data, size_t len)
        {
            _looper->push(data, len);
        }
        void realLog(Buffer &buf)
        {
            if(_sinks.empty()) return;
            for(auto &sink : _sinks)
            {
                sink->log(buf.begin(), buf.readAbleSize());
            }
        }
    private:
        AsyncLooper::ptr _looper;

    };

    enum class LoggerType
    {
        LOGGER_SYNC,
        LOGGER_ASYNC
    };

    class LoggerBuilder
    {
    public:
        LoggerBuilder()
            : _logger_type(LoggerType::LOGGER_SYNC),
              _limit_level(LogLevel::values::DEBUG),
              _looper_type(AsyncType::ASYNC_SAFE) {}

        void buildLoggerType(LoggerType type)
        {
            _logger_type = type;
        }
        void buildEnableUnsafeAsync()
        {
            _looper_type = AsyncType::ASYNC_UNSAFE;
        }
        void buildLoggerName(const std::string &name)
        {
            _logger_name = name;
        }
        void buildLoggerLevel(LogLevel::values level)
        {
            _limit_level = level;
        }
        void buildFormatter(const std::string &pattern)
        {
            _formatter = std::make_shared<Formatter>(pattern);
        }

        template <typename SinkType, typename... Args>
        void buildSink(Args &&...args)
        {
            LogSink::ptr psink = SinkFactory::create<SinkType>(std::forward<Args>(args)...);
            _sink.push_back(psink);
        }
        virtual Logger::ptr build() = 0;

    protected:
        AsyncType _looper_type;
        LoggerType _logger_type;
        std::string _logger_name;
        std::atomic<LogLevel::values> _limit_level;
        Formatter::ptr _formatter;
        std::vector<LogSink::ptr> _sink;
    };

    class LocalLoggerBuilder : public LoggerBuilder
    {
    public:
        Logger::ptr build() override
        {
            assert(_logger_name.empty() == false);
            if(_formatter.get() == nullptr)
            {
                _formatter = std::make_shared<Formatter>();
            }
            if(_sink.empty())
            {
                buildSink<StdoutSink>();
            }
            if(_logger_type == LoggerType::LOGGER_ASYNC)
            {
                return std::make_shared<AsyncLogger>(_logger_name, _limit_level, _formatter, _sink, _looper_type);
            }
            return std::make_shared<SyncLogger>(_logger_name, _limit_level, _formatter, _sink);
        }
    };

    class LoggerManager
    {
    public:
        static LoggerManager& getInstance()
        {
            static LoggerManager eton;
            return eton;
        }

        void addLogger(Logger::ptr &logger)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _loggers.insert(std::make_pair(logger->name(), logger));
        }

        bool hasLogger(const std::string &name)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _loggers.find(name);
            if(it == _loggers.end())
            {
                return false;
            }
            return true;
        }

        Logger::ptr getLogger(const std::string &name)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _loggers.find(name);
            if (it == _loggers.end())
            {
                return Logger::ptr();
            }
            return it->second;
        }
        Logger::ptr rootLogger()
        {
            return _root_logger;
        }

    private:
        LoggerManager()
        {
            std::unique_ptr<wzh::LoggerBuilder> builder(new wzh::LocalLoggerBuilder());
            builder->buildLoggerName("root");
            _root_logger = builder->build();
            _loggers.insert(std::make_pair("root", _root_logger));
        }
    private:
        std::mutex _mutex;
        Logger::ptr _root_logger;
        std::unordered_map<std::string, Logger::ptr> _loggers;
    };

    class GlobalLoggerBuilder : public LoggerBuilder
    {
    public:
        Logger::ptr build() override
        {
            assert(_logger_name.empty() == false);
            if(_formatter.get() == nullptr)
            {
                _formatter = std::make_shared<Formatter>();
            }
            if(_sink.empty())
            {
                buildSink<StdoutSink>();
            }
            Logger::ptr logger;
            if(_logger_type == LoggerType::LOGGER_ASYNC)
            {
                logger = std::make_shared<AsyncLogger>(_logger_name, _limit_level, _formatter, _sink, _looper_type);
            }
            else
            {
                logger = std::make_shared<SyncLogger>(_logger_name, _limit_level, _formatter, _sink);
            } 
            LoggerManager::getInstance().addLogger(logger);
            return logger;
        }
    };

}

#endif
